1. Field of the Invention
The present invention relates to a cleaning unit and a process cartridge which are used in an electrophotographic image forming apparatus, and to the electrophotographic image forming apparatus.
Herein, an electrophotographic image forming apparatus refers to an apparatus configured to form an image on a recording material (recording medium) by an electrophotographic method (electrophotographic image forming process).
Examples of the electrophotographic image forming apparatus include a printer (laser beam printer, light emitting diode (LED) printer, etc.), a copying machine, a facsimile apparatus, a word processor, and a multifunction peripheral (multifunction printer) of those apparatus.
2. Description of the Related Art
In the electrophotographic image forming apparatus (hereinafter also simply referred to as “image forming apparatus”), an electrophotographic photosensitive member as an image bearing member, which generally has a drum shape, in other words, a photosensitive drum is uniformly charged. Then, the charged photosensitive drum is subjected to selective exposure so as to form an electrostatic latent image (electrostatic image) on the photosensitive drum. Next, the electrostatic latent image formed on the photosensitive drum is developed into a toner image with toner as developer. After that, the toner image formed on the photosensitive drum is transferred onto a recording material such as a recording sheet of paper and a plastic sheet, and heat and pressure are applied to the toner image transferred onto the recording material so as to fix the toner image to the recording material. In this way, image recording is performed.
In general, such an image forming apparatus requires toner supply and maintenance of various processing units. In order to facilitate the toner supply and the maintenance, there has been practically used a process cartridge obtained by integrating the photosensitive drum, a charging unit, a developing unit, and a cleaning unit into a frame(s) of a cartridge, which is removably mounted to a main body of the image forming apparatus.
Image forming apparatus of such a process cartridge type enable a user himself/herself to perform maintenance of the image forming apparatus, and hence operability can be markedly enhanced. As a result, an image forming apparatus excellent in usability can be provided. For this reason, the image forming apparatus of the process cartridge type have been widely used.
As described above, a cleaning member as the cleaning unit configured to remove toner (residual toner) remaining on a surface of the photosensitive drum after the transfer step from the photosensitive drum is provided in the process cartridge. In some cases, it is desired that the cleaning member which abuts against the photosensitive drum be supported in a pivotable manner.
In a cleaning unit disclosed in Japanese Patent Application Laid-Open No. H06-161328, the cleaning member is supported in a pivotable manner with respect to the frame. Specifically, in the cleaning unit disclosed in Japanese Patent Application Laid-Open No. H06-161328, a support member for a cleaning blade is supported in a pivotable manner through pins by the frame, and the cleaning blade is pressed against a photosensitive member by springs.
However, the structure as described above, in which the cleaning member is supported in a pivotable manner through, for example, the pins, has problems in that a larger number of components and higher cost thereof are required, and the structure is liable to be complicated.